In certain situations, it is useful to be able to estimate the structure and motion of an object. For example, it is desirable to estimate the structure and relative motion of stationary or moving objects that an unmanned aerial vehicle (UAV) must avoid. In prior solutions to this problem, knowledge of the Euclidean geometry of the objects or full knowledge of the camera motion of the UAV is required. It would be desirable to have a system and method that do not require that knowledge.